Top quark physics is entering a new era of precision with the
recent results from Tevatron and initial LHC data. We discuss
the latest theory developments for cross section predictions
in channels relevant for precision studies of the Standard
Model as well as the role of top quarks in searches for the
Higgs boson and new physics beyond the Standard Model.
We present the first direct determination of the running
top-quark mass based on the total cross section measured
at the Tevatron and comment on the implications for
electro-weak precision fits.